A brief description of the general geology of the northern half of the Bannock Range is given as background for (1) interpretation of local structural-stratigraphic problems of the pre-Cambrian and lower Paleozoic, and (2) relation of local structures to those of the overthrust segment of the Putnam-Bannock thrust farther east,
Greatest deformation was during the Laramide epoch, and local structures are characterized by westward-overturned isoclinal folds. Faults of similar age are relatively unimportant. In contrast, folds of the overthrust segment of the Putnam-Bannock thrust are overturned eastward and are cut by numerous faults.
It is suggested that the Bannock Range is a large window exposed by erosion of the Putnam-Bannock thrust and that the Bannock Range structures originated in a segment underthrust relatively westward.